Nitroparawin solvent process for



Patented Oct. 18, 1949 NITROPA-HAFFI'N SOLVENT PROGESS-FOR- MAKING;OLEFI-N: NITROSOGHEORIDES Carl Bordenca and Wilbur, A... Lazier,Birmingham, Ala... assignors to Food Machinery and Chemical Corporation,a corporation of'Delaware NoDnawing. ApplicationrMarch 25,1947,SeriaLNo. 73, 7,102

5 Claims. 1

This invention, relates to a new and. improved process for convertingolefins. to their nitrosochlorides.

Olefins have heretoforebeen converted to. their nitrosochlorides bydissolving them in solvents such. as alcohols and. organic acids andpassing nitrosyl chloride through. the solution. The yields obtained bythese prior art processes are, however, unsatisfactory, and vary widelywith slight changesin the operating conditions.

It, is anobject of this. invention to convert olefins to theirnitrosochlorides by a new and improved process which produces highyields of the desired end product. A further object is to produce thesecompounds by a process which may be controlled readily and which issimple and economical. Additional objects; willobecome apparent from aconsideration of the following description and claims.

These objects are attained in accordance with our present invention,which involves the use of nitroparafiins as solvents for the olefinsundergoing reaction. In. a more restricted; sense our in;- vention isdirected to the employment oinitroparafi'ins having from one to eight,carbon" atoms as solvents in the reaction between, olefins and nitrosylchloride. Infa still; more limited sense this invention is concernedwith a process wherein olefins, particularly cyclic olefins, andpreferably those of the terpene group, are dissolved in a nitroparafiincontaining from one to four carbon atoms, after which nitrosyl chlorideis passed through the solution. One of the preferred embodiments of thisinvention involves carrying on the foregoing reaction while maintainingthe olefin-nitroparaffin solution at low temperatures, advisably below 0C. and preferably in the neighborhood of 35" C. for those nitroparafiinswhich are liquid at these temperatures.

The invention may be more readily understood by a consideration of thefollowing illustrative examples:

Example 1 Over a 1 hour period, 44 g. of nitrosyl chloride was bubbledinto a mixture of 100 g. of d-limonene in 200 cc. of nitromethane,maintained between C. and C. The mixture was stirred throughout theperiod and for an additional 0.25 hour at the above temperature. It wasfiltered and the precipitate washed with approximately 200 cc. of coldether. The solid nitrosochloride weighed 64 g.. representing a 43 percent conversion of the d-limonene.

It is to be noted that when the same procedure was followed and atemperature range of +5 C.

2 to +7 C; was employed; only 52g. of'd-limonene nitrosochloride wasobtained, representing a- 35 per cent conversion of 'the limonene.

Example 2 Overa period of 1- hour, 20- g. ofnitrosyl chloride wasbubbled into amixtureof 46g, ot'dlimonene in cc. of nitroethane,maintained between 40 C. and 50" C; The-mixture was stirredthroughoutthis period and for an additional 2.5' hours while it washeldwithin the above temperature range. Thesolid; d-limonene'nitrosochloride was isolated by filtration; washed with 200 cc. of coldether, andair-dried'; its weight was 26g, representing a 38pereent'conversion of the d-limonene.

Whereas; in the above examples it has been shown that conversion ofd-limonene to its nitrosochloride is obtained in certain solvents, itshould be noted that at temperatures of 0 C. or below the reactionapparently does not occur in carbon tetrachloride, carbon disulfide,ethyl acetate, benzene, and ether in the absence of high- 1y polarsubstances. In methyl, ethyl, and butyl alcohols conversions under 25per cent have been obtained.

In the above examples in place of thenitromethane and nitroethanesolvent theretmay be employed nitropropane, nitrobutane, nitropentane,nitroheptane, or nitrooctane, with satisfactory results. Likewise,isomers, as well as mixtures of such solvents, may be used. In the samemanner the nitro group may be substituted on any of the various possiblepositions in the alkane radical. It is also contemplated that highermembers of the nitroalkane series may be employed, although for optimumresults we prefer to use nitroalkanes having no more than eight carbonatoms in the molecule, and preferably from one to four carbon atoms.

It is to be understood that the conditions of reaction set forth in theforegoing examples may be varied considerably without departing from thescope of this invention. For example, the relative amount of thereactants may be varied substantially and the temperature and time ofreaction may likewise be varied considerably. As a general rule, it ispreferred to use temperatures below 10 C. and preferably in theneighborhood of 35 C. for those nitroparafiins which are liquid at thesetemperatures. which the olefin-nitroalkane solution is maintained atthese temperatures may be varied considerably in accordance withwell-known refrigeration technique.

The manner in This invention is applicable to the conversion of olefinsgenerally to their orresponding nitrosochlorides by treatment withnitrosyl chloride. The olefins may be either cyclic or acyclic innature. A representative group of cyclic olefins is, for example,cyclohexene, methyl cyolohexene, 8,9-dihydrolimonene, l-limonene,dipentene, ocpinene, fl-pinene, and the like. A representative group ofacyclic olefins is, for example, octane-1, octene-2, styrene, stilbene,hexadecene, octadecene, and the like.

It is to be understood that mixtures of one or more olefins may betreated in accordance with this invention. This is particularlydesirable in the case of those olefins which are difiicult to separatefrom their homologs, wherein the employment of a mixture substantiallyreduces the cost of the operation.

While this invention broadly contemplates the treatment of cyclic andacyclic olefins, it is to be understood that it is particularly adaptedto the conversion of cyclic olefins, especially those of the terpeneclass, to their corresponding nitrosochlorides. The preferred embodimentof this invention, as is evident from the above examples, is thetreatment of limonene, preferably d-limonene.

By means of the present invention a simple and economical process forthe production of nitrosochlorides is rendered available. This is animportant reaction, but heretofore, so far as we are aware, the yields,and therefore the expense of the operation, was unsatisfactory. We havenow found that this difliculty is in large measure attributable to theuse of an inefficient solvent system. The solvent system of ourinvention, particularly in conjunction with the employment of lowtemperatures, avoids these and other disadvantages inherent in the priorart.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope hereof, it is to beunderstood that the invention is not limited to the specific embodimentshereof except as defined in the appended claims.

We claim:

1. A process which comprises dissolving an olefin having at least sixcarbon atoms in a nitroparafiin having from one to eight carbon atoms,passing nitrosyl chloride therethrough at a temperature below 0 C., andthereafter separating the resulting nitrosochloride therefrom.

2. A process which comprises dissolving a terpene olefin in anitroparafiin having from one to eight carbon'atoms, maintaining thesolution at a temperature below 10 C., passing nitrosyl chloridetherethrough, and thereafter separating the resulting nitrosochloridetherefrom.

3. A process which comprises dissolving limonene in a nitroparafiinhaving from one to four carbon atoms, maintaining the solution at atemperature below 10 C., passing nitrosyl chloride therethrough, andthereafter separating the resulting limonene nitrosochloride therefrom.

4. A process which comprises dissolving d-limonene in nitromethane,maintaining the solution at a temperature below 10 C., passing nitrosylchloride therethrough, and thereafter separating the resultingd-limonene nitrosochloride therefrom.

5. A process which comprises dissolving d-limonene in nitroethane,maintaining the solution at a temperature below 10 C., passing nitrosylchloride therethrough, and thereafter separating the resultingd-limonene nitrosochloride therefrom.

CARL BORDENCA. WILBUR A. LAZIER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Beckham Mar. 18, 1947 OTHER REFERENCESNumber

